^Q ANALYSES OF METtOiUC STONES. 



posed to the air a sliglit flocculent precipitate of oxide of 

 manganese falls down. On filtering- afresh the solution has 

 a fine yellow colour, which would be supposed to b^ owing 

 to chrome. ' It was then saturated with nitric acid, and 

 evaporated to drj^ness. During this operation it assunaed 

 ilex. the appearance of a jelly, which indicated the presence of 



silex. The nitrate dried, and redissolved in water, commu- 

 nicated to it but a very slight tinge. The silex, which had 

 been separated, was perfectly white. The solution of ni- 

 trate of potash, tried in all ways with solutions of silver, 

 mercury, and lead, even after having been considerably con- 

 No chrome. centrated, did not exhibit the least sign of the presence of 



„ , , chrome. It appeared therefore, that the yellow colour of 

 Ydlow colour . . . "^ . 



from the j)lati- the solution was owing to a small quantity of platina taken 

 na ofihociu- ,,p j^y ^^^ potash from the crucible in which the stone had 



cible acted on ' *' ' 



by t!ie pe'ash. been treated. 



Rebi'Juum. ^he residuum, which had been separated from the green 



alkaline solution, was diluted in water, and supersaturated 

 •with muriatic acid, which dissolved it completely. This 

 solution, which had a fine yellow colour, was evaporated to 



Silex. dryness, then diluted in acidulous water, and filtered. The 



silex, collected on a filter, was perfectly white, and was add- 

 ed to that before obtained. 



Muriatic solu- The muriatic solution freed from silex was of a lemon 



**""• colour. Being decomposed liy ammonia in considerable ex- 



cess, a very bulky brown precipitate was formed, which was 

 collected on a filter. To the ammoniacal liquor oxalic acid 

 was added, which produced a very copious precipitate of 



Lime. oxalate of lime. This was carefully filtered. Though the 



solution was colourless it was evaporated to dryness; and, 

 after having been strongly heated, to volatilise part of the 

 sal ammoniac, it was redissolved in water, and made to boil. 

 Oil adding some potash a light black precipitate was ob- 

 tained, which was carefully collected. This precipitate, 

 ■while still wet, was dissolved in muriatic acid. The solu- 

 tion, which was yellow, was diluted with a pretty large 

 quantity of water, and decomposed by saturated carbonate 

 of potash, which occasioned some light flocks, that could 

 not be collected without great trouble. The colour of these 

 flocks was a greenish white ; and they dissolved in ammo- 

 nia. 



